New Magnepan "Concept Speaker" introduced at Audio Connection

What BDP24 said -- four monopoles are as smooth as two dipoles, but the backwave of a dipole will cancel with the backwave of a monopole, so the crossover will always be somewhat problematic.

Another consideration here is that the 30.7FC is intended to address the needs of the "conflicted couple." The ability to hide the woofers was an important consideration in the design. 

Hello bdp24 and josh358,

     Have you two gentlemen ever listened to a pair of the Magnepan DWM dipole woofer panels? I intentionally described them as woofer panels, as opposed to subwoofer panels, because they only have rated bass output extension down to 40 Hz. I’ve listened to all the latest Magnepan speakers, all 3 top models from the 3.7i on up to the 30.7, combined with a pair of DWM dipole woofer panels and the bass they contribute is very well integrated with all 3 pairs of main speakers but their bass contributions always sounded to me as no deeper or impactful than mid-bass
     Heck, each of my Magnepan 3.7i speakers basically have a large built-in dipole woofer section that are rated to have bass output extension deeper than the DWMs, down to 35 Hz. I run the 3.7i pair full-range and utilize the 4-sub AK Debra DBA system, with all 4 subs powered by the included 1,200 watt class AB amp/control unit and the crossover control set at 40 Hz, to supplement the bass in my system from 20 to 40 Hz.
     From first hand experience using the monopole 4-sub AK Debra system with large 6’x2’ 3-way Magnepan dipole planar-magnetic panel speakers (initially the 2.7QR and now with the 3.7i) for the past 4 years, I can state with certainty that the bass produced by the AK 4-sub DBA system is just as fast, smooth, effortless, natural, detailed and seamlessly integrated with my main panels as the dual DWM bass panels I’ve heard, but with significantly better bass impact, dynamics and extension. It’s the difference between hearing some additional mid-bass emphasis and hearing as well as feeling the bass as experienced when music is heard and felt played live in person.
     I’ve always respected Duke’s knowledge and experience and am aware he has made very positive statements in the past about the general bass quality produced by open baffle, line source and dipole speakers and subs. If he ever made the statement bdp24 has claimed, however, I seriously doubt Duke was referring specifically to comparing the bass performance of a pair of Magnepan dipole DWM panels to the bass performance of his AK Swarm or Debra monopole 4-sub DBA system. The differences in their bass performance quality are just too obvious and stark.
     Jdp24 made the following 2 related statements:
#1: "The monopole characteristics of sealed and ported subs is a major factor in making the seamless integration of planars and subs as unsuccessful as so many have found it to be. Magnepan chose to go with an OB/Dipole woofer system in the proposed new model for exactly that reason.?"

#2: "The distributed array bass system addresses the problem of bass/room interaction, but does nothing to address the issue of the difference between monopole and dipole propagation. OB/Dipole woofers eliminate that difference. "

     Both of these statements are demonstrably false and just serve to acknowledge your obvious lack of knowledge of, and experience with, the 4-monopole sub DBA concept that’s been scientifically proven to be remarkably effective in virtually any room and with any pair of main speakers by 2 separate PHD acoustical scientists, Dr. Earl Geddes and Dr. Floyd Toole,
     You and any thread readers interested in research on the acoustics of attaining exceptionally good in-room bass response in domestic sized rooms can google both of these names and find an abundance of factual information on how and why the 4-sub DBA concept was developed based on these men’s research, along with the related contributions of Duke Lejeune and Todd Welti.

Tim

I don't think anyone was questioning the quality of a four-woofer array. The research demonstrating that is well known, and as I said, a speaker designer I know (who played a role in the development of the new Maggie) compared four sealed woofers with two planar woofers and found their quality comparable.

I'd point out, though, that the new woofer is *not* a DWM, or a planar woofer at all. It's a dynamic dipole woofer that has response similar to the response of the 30.7's bass panels. Which is to say it isn't a sub, but neither is it a DWM, which is designed to reinforce the midbass and has limited output. It's designed to be small and easy to hide, though the woofers can be stacked in a large room.

(I wonder what happens when you use four dipole woofers in an array? It could potentially be smoother than either four monopoles or two dipoles!)